X-ray barriers

The calculations presented below follow the recommendations and tables from reference [1]. The code calculates the thickness of the shielding necessary to reduce the exposure at levels permitted by regulations, for an X-ray source that can generate up to 300 keV.
It is considered controlled areas with maximum annual exposure of 50 mSv or 20 mSv.
For uncontrolled areas, a maximum annual exposure of 5 mSv and 1 mSv is considered. The maximum annual exposure of 0.05 mSv is added for ALARA considerations.
The results are done for lead, concrete and drywall. The values for drywall are only approximated.

For the total thickness of the secondary barrier, the following criteria are used: if the difference between the leakage thickness and the scattered thickness is lower than the TVL, then the total thickness is equal to the bigger of both values plus a HVL. If the difference is bigger than a TVL, then the bigger thickness will suffice.

The distance d2 and d3 are used also to calculate the angle of scattering. This angle is approximated to 30, 45, 60, 90, 120 or 135 degrees in order to select the correction factor

Definitions:

Controlled area = A defined area in which the exposure of persons to radiation is under the supervision of a Radiation Protection Supervisor (the area requires control of access, occupancy and working conditions).

Uncontrolled area = an area to be occupied by public.

Occupancy factor = Occupancy is the fraction, expressed as a percentage, of the time the area will be occupied while the source is on.